Formation times

They are formed by treatinga-diketones, a-hyd-roxyaldehydes, hydroxyketones, aminoalde-hydes or aminoketones with arylhydrazines. Sugars can be identified by their osazones which have characteristic melting-points, formation times or crystal appearance. 

A recent design of the maximum bubble pressure instrument for measurement of dynamic surface tension allows resolution in the millisecond time frame [119, 120]. This was accomplished by increasing the system volume relative to that of the bubble and by using electric and acoustic sensors to track the bubble formation frequency. Miller and co-workers also assessed the hydrodynamic effects arising at short bubble formation times with experiments on very viscous liquids [121]. They proposed a correction procedure to improve reliability at short times. This technique is applicable to the study of surfactant and polymer adsorption from solution [101, 120]. 

Fits some, but not all, data. Low mass transfer rate. = mean molecular weight of dispersed phase tf= formation time of drop. k[, i = mean dispersed liquid phase M.T. coefficient kmole/[s - m" (mole fraction)]. 

E] Used with log mean mole fraetiou differeuee. 2.3 data points. Average ahsolute deviatiou 25%. tf= formation time. 

In a top-feed filter test, the filter cake will contain all of the solids, provided they are all emptied from the sample container. The danger in this type of test is that the solids will stratify, particularly if the c e formation time is prolonged. Close examination of the filter cake will... 

It is difficult to plan a filtration leaf test program until one test has been run. In the case of a bottom-feed test, the first run is normally started with the intention of using a 30-s cake formation time. However, if the filtrate rate is very high, it is usually wise to terminate the run at the end of 15 s. Should the filtrate rate be very low, the initial form period should be extended to at least 1 min. If cake washing is to... 

Electrochemical corrosion is understood to include all corrosion processes that can be influenced electrically. This is the case for all the types of corrosion described in this handbook and means that data on corrosion velocities (e.g., removal rate, penetration rate in pitting corrosion, or rate of pit formation, time to failure of stressed specimens in stress corrosion) are dependent on the potential U [5]. Potential can be altered by chemical action (influence of a redox system) or by electrical factors (electric currents), thereby reducing or enhancing the corrosion. Thus exact knowledge of the dependence of corrosion on potential is the basic hypothesis for the concept of electrochemical corrosion protection processes. 

The process of vibration analysis requires gathering complex machine data and deciphering it. As opposed to the simple theoretical vibration curves shown in Figures 43.1 and 43.2, the profile for a piece of equipment is extremely complex. This is tme because there are usually many sources of vibration. Each source generates its own curve, but these are essentially added together and displayed as a composite profile. These profiles can be displayed in two formats time-domain and frequency-domain. 

Growth, substrate utilisation and product formation time courses exhibit coincident maxima. 

R Chiral Additive Equiv Complex Formation Time Temp. (X) ee (%> Config. of 25a Yield (%)... 

Linking the ketone and carboxylic acid components together in an Ugi reaction facilitates the synthesis of pyrrolidinones amenable to library design. The three-component condensation of levulinic acid 30, an amine and isocyanide proceeds under microwave irradiation to give lactams 31 [65]. The optimum conditions were established by a design of experiments approach, varying the equivalents of amine, concentration, imine pre-formation time, microwave reaction time and reaction temperature, yielding lactams 31 at 100 °C in poor to excellent yield, after only 30 min compared to 48 h under ambient conditions (Scheme 11). 

Charged particle tracks in liquids are formally similar to cloud chamber or bubble chamber tracks. In detail, there are great differences in track lifetime and observability. Tracks in the radiation chemistry of condensed media are extremely short-lived and are not amenable to direct observation. Also, it must be remembered that in the cloud or bubble chamber, the track is actually seen at a time that is many orders of magnitude longer than the formation time of the track. The manifestation occurs through processes extraneous to track formation, such as condensation, formation of bubbles, and so forth. In a real sense, therefore, charged particle tracks in radiation chemistry are metaphysical constructs. 

Based on currently available elemental abundance data and age determinations, the thick disk could have formed either through a violent, heating merger or through accretion of (substantial) satellites in a hierarchical galaxy formation scenario. The fast monolithic-like collapse is getting more and more problematic as data are gathered. It would be especially crucial to establish if there is an age-metallicity relation in the thick disk or not as in that case the thick disk could not have formed in that way (since the models indicate that the formation time-scale for the stars in the thick disk would be very short, see [7]). 

To be (a bit) more realistic, we consider again two of the models of Section 10.3.3. The abundance in a stellar atmosphere is the initial abundance given by Eq. (10.12) with A replaced by the formation time t of the star (with age T — t), modified by a factor g-W-0, jue (() subsequent free decay. Thus in the modified Fowler model we have from Eq. (10.18)... 

Since the y values under the integral sign are the values at t and not at the time T the crustal segment formed, a correction for decay over t — T brings us back to the formation time... 

The time ie represents the entanglement formation time at the current shear rate. The second term g is the average number of entanglement sites for a chain of fixed length in steady flow relative to the number in the zero shear rate limit ... 

The flow rate is then corrected by a ratio of the weeping time to the cycle time. Next the discharge time constant (RD C) of the capacitor is determined. If this is shorter than formation time, the entire capacitor expansion is added to bubble volume. If not, the same percentage of the capacitor expansion volume is added because the formation time is of the order of the capacitor discharge constant. The final value thus obtained forms the starting point for the next iterative step. This is continued till the values from two successive iterations are nearly the same. 

The transient assigned to TCC formed more slowly in 1-butanol for N-isobutyl NOSI3 (12.3 psec) than for NOSI3 itself (7.6 psec) however, no solvent viscosity effect was observed among the formation times in 1-propanol (12.6 psec), 1-butanol (12.3 psec), and 1-decanol (13.0 psec) for the same 77-isobutyl NOSI3. 

A technique frequently used to characterize the pressure state in the high vacuum regime is the calculation of the time required to form a monomolecular or monoatomic layer on a gas-free surface, on the assumption that every molecule will stick to fhe surface. This monolayer formation time is closely related with fhe so-called impingement rate z. With a gas at rest the impingement rate will indicate the number of molecules which collide with the surfece inside the vacuum vessel per unit of time and surface area ... 

If a is the number of spaces, per unit of surface area, which can accept a specific gas, then the monolayer formation time is... 

With the acceptance of the atomic view of the world - accompanied by the necessity to explain reactions in extremely dilute gases (where the continuum theory fails) - the kinetic gas theory was developed. Using this it is possible not only to derive the ideal gas law in another manner but also to calculate many other quantities involved with the kinetics of gases - such as collision rates, mean free path lengths, monolayer formation time. 

Therefore, in UFIV (p < 10 mbar) the monolayer formation time is of the order of minutes to hours or longer and thus of the same length of time as that needed for experiments and processes in vacuum. The practical requirements that arise have become particularly significant in solid-state physics, such as for the study of thin films or electron tube technology. A UFIV system is different from the usual high vacuum system for the following reasons ... 

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